expand                  Expand data frame to include all combinations
                        of levels.
extract                 Extract one column into multiple columns.
extract_numeric         Extract numeric component of variable.
gather                  Gather columns into key-value pairs.
separate                Separate one column into multiple columns.
seq_range               Create an evenly spaced sequence of values from
                        highest to lowest.
spread                  Spread a key-value pair across multiple
                        columns.
spread_                 Standard-evaluation version of 'spread'.
unite                   Unite multiple columns into one.
unnest                  Unnest a list column.
unnest_                 Standard-evaluation version of 'unnest'.
